Multiple Myeloma

• Clinical

• Average age is 60-70

• Men much more common than women

• Most have an elevated serum protein with 80-90% in the globulin fraction, especially IgG

• Bence-Jones protein in 40-60% of patients (light chains)

• X-ray findings

• Osteoporosis is most common skeletal abnormality in this disease

• Lesions are usually multiple and found in vertebrae, ribs, skull, pelvis, and femur

• Over 50% of solitary lesions are found in vertebrae

• Mandible involved in 1/3 of patients with diffuse involvement

• Widespread lucencies in bone

• Discrete, “punched-out” lesions

• Uniform in size

• Distinctive to MM are the lucent, elliptical, subcortical shadows, especially in long bones=endosteal scalloping

• Due to buttressing since MM is usually a slower process than mets

• In spine, MM destroys body and spares pedicle

• DDX: mets and disuse osteoporosis

• MM is more widespread

• More discrete holes in MM

• Large foci of coalescence more often due to mets

• Severe disuse osteoporosis may simulate bone changes of MM

• Sclerosis is usually seen only with treatment or fracture

• Bone scans may typically be negative and many hot  areas on scan may be healing fractures

• Most believe that almost all patients with a solitary plasmacytoma will develop multiple myeloma

• Solitary plasmacytoma produces “soap-bubbly” expansile, septated lesion, when characteristic

Multiple myeloma. The pelvis contains numerous lytic lesions without reactive sclerosis which have an almost "soap-bubbly" appearance in the ischia. There are also lytic lesions in
both proximal femora.



Multiple myeloma. The skull contains innumerable small lytic lesions of more-or-less uniform size. This has been likened to an "oil-droplet" appearance. Metastases are generally fewer in number and of different sizes and shapes.

Other examples of Multiple Myeloma (Mouse over to enlarge)